Statistical Analysis for Decision Makers in Healthcare, Second Edition: Understanding and Evaluating Critical Information in Changing Times Book

Introduction xi

Section I The Scientific Foundations of Statistical Analysis

Chapter 1 Scientific Method: The Language of Statistical Studies 3

Science as a Universal Language 5

The Attributes of Scientific Method 8

Science Is Open-Minded 8

Science Is Free of Values 9

Science Is Thoughtful 10

Science Is Reproducible 11

Science Is Honest 13

The Attributes of a Scientific Report 14

Abstract 15

Introduction and Problem Statement 16

Review of Literature 17

Methods (Methodology) 18

Data 19

Results and Discussion 20

Chapter 2 Experimentation: The Foundation of Scientific Studies 23

What Is an Experiment? 24

The Hypothesis 26

The Experiment 28

1 Randomly Select the Study Sample from the Population 29

2 Randomly Assign the Study Sample to Experimental and Control Groups 31

3 Establish Pretest (Baseline) Measures for Experimental and Control Groups 32

4 Administer an Experimental Effect to an Experimental Group Only 33

5 Establish Posttest Measures for Experimental and Control Groups 33

6 Analyze Experimental Data for Statistical Significance 33

Evaluation Studies 34

Section II The Fundamental Importance of Data

Chapter 3 Numbers Good and Bad: How to Judge the Quality of Data 39

Letting the Numbers Speak for Themselves 40

What Are Data? 42

Validity 43

Reliability 45

Location Bias 46

Sex Sampling Bias 47

Dollar Measurement Bias 47

Counting Error 49

Definitional Error 49

Adjustment Error 49

Time Measurement Error 50

Types and Levels of Measurement 52

Parametric Data 53

Nonparametric Data 54

Chapter 4 Samples and Surveys: How Numbers Should Be Collected 57

Sample Selection 57

Sample Size58

Response Rate 62

Information Systems 64

Survey Research 65

Survey Bias 66

Respondent Objectivity 67

Survey Format 69

Data Extraction 71

Section III The Different Types of Statistics

Chapter 5 Descriptive Statistics: The Foundation of Comparisons 77

The First Step: What Have We Here? 78

Descriptive Analysis 78

Range 80

Measures of Central Tendency 83

Median 84

Mode 84

Mean 87

Measures of Dispersion 89

Overview 89

Standard Deviation 91

Chapter 6 Inferential Statistics: Studies of Differences 97

The Normal Distribution 98

The Central Limit Theorem 103

Standard Error (of the Mean) 104

Quick Review 106

Hypothesis Testing 106

Accepting the Null Hypothesis 111

Rejecting the Null Hypothesis 111

Test Statistics 114

t Test 116

F Test (Analysis of Variance) 116

Chi-Square Test 119

The End of the Tunnel 123

Chapter 7 Relational Statistics: Studies of Relationships 125

Direction of Relationships 126

Strength of Relationships 127

Test Statistics 130

Parametric Correlation 130

Nonparametric Correlation 132

Linear versus Nonlinear Relationships 132

Correlation and Causality 134

Chapter 8 Explanatory Statistics: Studies of Causality 137

Statistical Models 138

The Basic Equation of Multivariate Linear Regression Model 140

Specifying the Model 141

Evaluating a Multivariate Linear Regression Model 144

Refining Regression Models 150

Applications of Explanatory Statistics 150

Postscript: Statistics in Perspective 153

Index 155

About the Author 157